03 mdx all cylinders misfiring
10-08-2015, 08:38 AM
#1
03 mdx all cylinders misfiring
So yeah basically my 03 mdx pulled a check engine and vtm4 light, code reader said all cylinders are misfiring. My husband is car savy so we did the oil change, spark plug check, egr ports are clean, and did a valve adjustmemt. Wtf? I read that all that would help, and its not. It idle roigh at cold start then smooths out after 30 secs. Any thoughts or opinions wouls be helpful. Thanks!
10-08-2015, 08:49 AM
#4
yes, maybe 02 sensors have gotten lazy over time and making it run rich.
I would start by making sure that it is ACTUALLY a misfire and not carbon build up, like you guys think.
this would mean, combing through the records to see if the timing belt and water pump have been changed, and on time.
if not changed, the belt can either snap or stretch and make the engine fall out of of timing and break things internally, causing misfires.
same for the water pump, it can leak and over time cause the engine to over heat, breaking things inside the engine and causing a misfire.
the next step would be to perform a leak down and compression test to make sure all cylinders are holding compression and are not leaking.
I would start by making sure that it is ACTUALLY a misfire and not carbon build up, like you guys think.
this would mean, combing through the records to see if the timing belt and water pump have been changed, and on time.
if not changed, the belt can either snap or stretch and make the engine fall out of of timing and break things internally, causing misfires.
same for the water pump, it can leak and over time cause the engine to over heat, breaking things inside the engine and causing a misfire.
the next step would be to perform a leak down and compression test to make sure all cylinders are holding compression and are not leaking.
10-08-2015, 09:03 AM
#5
Mileage is 166. I think the previous owners took it to acura, well i sure hope so at least. Would make record finding easier. Thanks! Ill take a look at it today and let you guys know if i find anything. I read about running seafoam through it, would that help clean it out? Idk, im grasping now.
10-08-2015, 09:07 AM
#6
^right, the results of the leak down and compression test, will tell you if your misfires are related to compression problems or leaks.
this way, instead of throwing money at little tiny bandaid fixes (we dont know if the seafoam will work or not) you will know for sure, if the vehicle is misfiring or not.
if results come back with no leaks and uniform compression across the board, you'll know it's not a REAL misfire.
if test results come back poor, you'll know that the heads are bad from piston to valve contact and can take the necessary actions to fix your engine
this way, instead of throwing money at little tiny bandaid fixes (we dont know if the seafoam will work or not) you will know for sure, if the vehicle is misfiring or not.
if results come back with no leaks and uniform compression across the board, you'll know it's not a REAL misfire.
if test results come back poor, you'll know that the heads are bad from piston to valve contact and can take the necessary actions to fix your engine
10-08-2015, 10:05 AM
#9
he could have tightened the valves too tight, which wont let them move, when the engine calls for them to move.
they work in-sync with pistons.
IF too tight,a piston could have kissed a valve.
another compression test and leak down test is in order, the results WILL tell you if you lost compression and in which cylinder
they work in-sync with pistons.
IF too tight,a piston could have kissed a valve.
another compression test and leak down test is in order, the results WILL tell you if you lost compression and in which cylinder
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